How Does a Hybrid Car Work? Hybrid vs Plug In EV Cars (Battery, Gas, Charging)

Georgette Kilgore headshot, wearing 8 Billion Trees shirt with forest in the background.Written by Georgette Kilgore

Carbon Offsets Credits | May 31, 2023

Man looking at a hybrid vehicles wonders how does a hybrid car work and what are the pros and cons of hybrid car battery and any hybrid car benefits, and is there a best hybrid car or hybrid suv and what are the hybrid vs plug in hybrid stats?

Have you ever asked yourself, how does a hybrid car work?

Hybrid electric vehicles (HEV)’s are powered by both an internal combustion engine and one or more electric motors, which is designed to reduce emissions.

In most standard hybrids, high-voltage batteries for the motor are charged with regenerative braking (discussed below) and by the combustion engine.

In some other models, the batteries are chargeable by an external source. The advantages of having these two power sources almost always mean burning less gasoline and, as a result, better gas mileage (or fuel economy) and less pollution.

In certain instances, the system can also contribute to higher performance.

What Is a Hybrid Car? (How Does a Hybrid Car Work?)

How does a hybrid car work? Well, there are different ways a hybrid car can supply power to its drive train.

Graphic representation showing how a hybrid car works. It starts by starting it up, then low-speed driving, followed by accelerating fast, then fast driving, followed by slowing down, and then lastly, stopping.

The following methods are the main ones:

  • Parallel hybrids: In this type, both the combustion engine and the motor are connected to the mechanical transmission and can power drive the wheels simultaneously.
    This happens most often through a conventional transmission. The combustion engine of parallel hybrids can also act as a generator battery for the electric motor.
    Around 2013 such hybrids were only designed for the motor to supplement the engine, but after 2015, many parallel hybrids enabled electric driving up to moderate acceleration. They are well suited for both stop-and-go and highway driving.
  • Series hybrids: With this type, the drive train is powered exclusively by the electric motor, and the combustion engine serves as a generator to charge the batteries.They usually have a larger battery pack and thus increased cost.
    They are well suited for city driving. This arrangement is most commonly found in PHEVs.
  • Power-split: This type is a ‘hybrid.’ In other words, it combines features of both parallel and series hybrids.
    Thus they are more efficient overall, but more expensive.

There is another potential division in types, between mild hybrids (aka micro-hybrids) and full hybrids.

  • Mild hybrids use their battery and motor to help power the driver and can sustain power when the vehicle is stopped, but they cannot power drive by themselves.They are usually cheaper than full hybrids but provide less benefit to fuel economy.
  • Full hybrids have larger motors and batteries, they can power the car without combustion help for short distances and under slight demands.1

What Is the Carbon Footprint of Electric Cars vs Gasoline? (Engine vs Motor)

Due to their use of electrical power, the carbon footprint of electric cars vs gasoline is usually less. However, different electric cars work in different ways.

For hybrid drive, the hybrid battery stores energy from waste combustion energy or from an external charger to power the car. Pure EVs charge their batteries with external charge.

In each case, it means less requirement to burn gas for power. In the case of external charging, there is a question of the energy supplied.

For example, coal can be used to generate electricity for a car battery, which is not necessarily more sustainable than using petrol.

However, power grids are using more and more sustainable energy, so it is a safe bet that in the modern case, electrical power for cars has a lower carbon footprint than gas power.

Yet, that doesn’t mean it’s completely emissions free.

Hybrid Car Features: How Do Hybrid Cars Work?

There are three main ways that Hybrids-Electric vehicles (HEVs) exploit the combination of engine and motor.

A white electrical car charging from its front charging port on a charging station with snow on the side of the driveway.

(Image: IsmaelMarder20)

They are:

  1. Regenerative Braking: The electricity of hybrid cars is stored in high-voltage battery packs. In a normal car, during braking, energy is lost as heat.
    A hybrid car can actually capture the energy released from the braking system and use it to charge the battery.
  2. Dual Power: At certain moments, it may be more efficient for the car to produce power from either the motor or the engine. Hybrid cars have the ability to make this choice and adapt the primary power source to driving conditions.
    There are many considerations. For example, the electric motor is often more efficient for low-speed driving whereas engine augmentation is more efficient at high speeds.
  3. Automatic Start and Shutoff: A hybrid car can automatically shut off the engine when stationary and restart it for acceleration. That’s because an electric motor makes this automation highly efficient.

For more explanation on electric vehicle technology see this Department of Energy explanation.2,11

Regenerative Braking (Regeneration Definition and Receptacle Definition)

Regenerative braking slows down an automobile by using an electric traction motor to capture the kinetic energy that would else be lost to the brake disks as heat. This can improve vehicle efficiency, generate power, and extend the life of a braking system.

Cars are not the only class of vehicles that exploit this technology. Different types of vehicles store energy in different ways, but in cars, there are basically three ways.

With a battery, chemically, with a capacitor bank, electrically, or by the mechanism of a rotating flywheel. As a driver, the feeling of regenerative braking is one of the most readily noticeable differences between driving a conventional hybrid and a conventional ICE.3

Example: Tesla Model S

Under normal driving conditions, the Tesla Model S will engage regenerative braking when the driver removes their foot from the accelerator. It offers different settings.

A Tesla Model S with its glossy black paint color in the middle of the street.

(Image: Josbert Lonnee21)

The “Standard” setting is the greatest engagement of the function. The “Low” setting engages less, which means less captured energy but a greater ability to coast with your foot off the gas.

There are additional settings for how the systems work when at low speed or stationary. “Creep” mode disengages regenerative braking when the driver’s foot is off the accelerator and applies slight motor torque to imitate the idling speed of a standard ICE vehicle.

“Roll” mode operates the same way but it applies no torque, allowing the car to roll freely, imitating a vehicle in neutral. “Hold” mode means regenerative braking will engage until the vehicle comes to a stop, which saves the brakes from wear and captures energy.

Once the car is stopped it engages friction brakes which means the vehicle will stand still until the driver applies his foot to the brake or accelerator.

Regenerative braking varies greatly between vehicle types and models. This is just one example of how the technology has developed into a highly refined product.3

Car Battery: How Does a Hybrid Car Work?

The question of ‘How does a hybrid car work?’ often leads to an explanation of the battery. Here is a guide on different types of battery.12

Close up of the engine bay of a white Toyota EV 86 with a car manual sheet placed on top during a car presentation.

(Image: Tokumeigakarinoaoshima22)

The standard battery for a combustion vehicle is lead-based – hardly environmentally friendly. Most batteries used in EVs are lithium-ion batteries.

The biggest producer at the moment is Panasonic, thanks to their partnership with Tesla. Another option is nickel-metal hydride.

However, lithium-ion has quite a few advantages. Lithium-ion batteries have the highest energy density among rechargeable batteries.

They can produce three times the voltage of a nickel-metal hydride cell while storing large amounts of electricity. They have high output, are highly efficient, and are extremely durable.

Most modern lithium-ion batteries will last as long as the cars in which they operate. Usually, lithium-ion batteries allow for less battery weight and can contribute to a 30% improvement in fuel economy when compared to combustion vehicles.

They are also safer to recycle. Volkswagen was the first to pioneer lithium-ion battery recycling and they have since been followed by other manufacturers.4

Environmental Impact of Hybrid Batteries

There is some disagreement as to the relative toxicity and environmental harm between various types of batteries. However, there is a consensus that lithium-ion batteries are more environmentally friendly than nickel metal hydride batteries previously common in hybrids.

This is due in part to relative toxicity. Various nickel compounds, like nickel chloride and nickel oxide, are known carcinogens.

The biggest environmental hazard with lithium-ion batteries comes with the extraction of raw materials, such as cobalt and lithium. For example, around 500,000 gallons of water are required to mine one metric ton of lithium.

Chile is the world leader in lithium production and the mines are in diverse ecosystems. In the Salar de Atacama region, one of the driest places on earth, about 65% of the water is used to mine lithium.

This creates a shortage for farmers and other locals. Working conditions are often exploitative.

And the environment suffers the effects of destruction associated with contemporary industrial mining.

And then there is the disposal issue. Lithium-ion batteries contain various toxic metals and can sometimes cause fires in landfills when improperly disposed of.

The best option is recycling, and serious investment has been made towards this end. Tesla, for example, has a fairly advanced system.

For years they worked with third-party recyclers, but recently have developed a recycling operation at their Gigafactory battery plant in Nevada. It is focused in particular on recovering various metals such as lithium, cobalt, copper, aluminum, and steel.

They claim to be able to repurpose over 90% of their battery’s material.

Click here for a full guide on lithium-ion battery disposal and recycling.5,13

How Much Do Hybrid Cars Cost?

Hybrid cars can cost a bit less, around the same, or a lot more than their pure combustion-engine counterparts.

One of the most attractive features of hybrid cars is the potential to save money in the long term with reduced fuel consumption.14

Close up of a yellow Toyota CHR Hybrid SUV car parked in a parking slot with other cars and motorcycles parked along the same area.

(Image: GeorgeTan#1…Off permanently23)

It is impossible to accurately predict the amount of savings, as this is dependent on factors like the type and amount of driving, gas prices, and life of the car. However, many customers have reported gas savings more than paying for the difference of choosing a hybrid.

The most savings will likely be for those who drive to work in urban conditions.

History of Hybrid Cars

In 1889 William H Patton filed his patent for a gasoline-electric hybrid rail-car propulsion system. Soon after, he patented a similar system for boats.

Patton began testing his Patton Motor car, a hybrid system for tram cars and locomotives. It was quite simple.

A gas engine charged a battery in parallel with the motors. He had some success with an experimental tram in Pullman, Illinois, and sold a locomotive to a company in Iowa.

The next step was in 1896. Harry Dey developed the Armstrong Phaeton.

It had a 6.5 liter 2 cylinder engine and a battery connected to a dynamo flywheel.

The battery was charged with the dynamo and regenerative braking. This automobile was the first to use semi-automatic transmission.

The vehicle was so powerful, its action damaged the wheels. At the turn of the century, Henri Pieper introduced a hybrid automobile with an electric motor, batteries, and a gas engine.

From there the technology continued to progress incrementally, accelerated by the technological drive of WWII. The biggest breakthrough came with regenerative braking in 1967 by American Motors Amitron.

Victor Wouk earned his title as the “Godfather of the Hybrid” in the 1960s and 70s, and companies like Audi, Alfa Romero, and BMW pursued the technology into the 90s

Hybrid technology became widespread in the late 1990s. The first mass-produced hybrid was the Toyota Prius, launched in Japan in 1997.

As of April 2020, more than 17 million hybrid electric vehicles have been sold worldwide since their inception in 1997. The market for hybrids is predominantly Japan and the USA, followed by Europe, Canada, and Australia.

The rise of fully electric vehicles and their supportive infrastructure has made hybrid cars trajectory into the future somewhat uncertain.1

Anyone who wants to learn more can check out this basic fact sheet on Hybrid Electric Vehicles.1,10

Pros and Cons of a Hybrid Car: Advantage and Disadvantage of Hybrid Car) (Hybrid vs Gas Car)

To help you understand the advantage and disadvantage of hybrid car, here are some of its pros and cons (hybrid vs gas car):

Pros: Environmental Impact

First, when compared to gas cars, hybrid cars are considered environmentally friendly as it pertains to fuel consumption. The gas consumed and exhaust produced by traditional combustion engine cars have various negative impacts on the environment.

According to the U.S. Environmental Protection Agency (EPA), a typical car in the USA emits 4.6 metric tons of carbon dioxide a year – not to mention all the other toxic and greenhouse gasses in the exhaust.

A hybrid uses electricity to capture energy from combustion that would otherwise go to waste, and improve the efficiency of power, especially during start-stop driving, which means less fuel consumption.

Cons: Environmental Impact

Although Hybrids are considered more environmentally conscious than combustion engine cars, they are considered less environmentally conscious than EVs. Pure EVs are usually more efficient and don’t consume any gas or emit exhaust into the environment.

The counter to this is that the electricity produced in the power grid to charge EVs is not always sustainable, for example, much of it comes from coal. However, more and more power is being supplied to North American grids from renewable sources every year.

And there are now applications like Wattime which allow consumers to know when their electricity is supplied by renewable sources. This means there is greater consumer control and in theory your EV could be charged with 100% renewable energy.

For an analysis of emissions attributed to different kinds of EVs, check out this Department of Energy release.15 Also, many hybrid cars use nickel-metal hydride batteries.

Both material sourcing and disposal are detrimental to the environment. Pure combustion cars and most pure EV cars use different kinds of batteries.

If you are going to buy a hybrid car, the most environmentally friendly option is likely one with a lithium-ion battery.

Pros: Saving Money

Saving fuel means saving money. Many hybrid owners have found that over the life of their hybrid, they have spent less on it than they would have on a pure combustion vehicle.

The exact amount of potential savings is heavily dependent on factors like the type of driving done. Also, the ticket price of hybrids is often lower than that of pure EVs.

Also, the federal government offers tax credits for plug-in hybrids (PHEVs), and various states may have incentives as well.

Cons: Losing Money

Although a hybrid could potentially save you money, there are sometimes extra costs associated with them. As mentioned, they usually have a higher ticket price than pure combustion vehicles.

Because of their combined power, they are also more expensive to maintain and repair. The savings on gas with a hybrid vehicle might also be lower than those which would be achieved by buying a pure EV.

Also, pure EV vehicles usually have greater eligibility for federal and state financial incentives.6

Hybrid Car Benefits (Are Hybrid Cars Worth It?)

Hybrid cars are designed to use less fuel combustion than exclusively combustion engine vehicles. So benefits of hybrid cars come in way of fuel economy and environmental impact.

For a more specific evaluation of your potential for financial savings with a hybrid, consult this webpage.16

Hybrid SUV

SUVs are one of the most popular classes of vehicles for hybrid options.

The weight and physical form of an SUV result in greatly increased gas mileage.

A brand new white Cadillac Escalade Hybrid SUV car displayed in a car showroom.

(Image: IFCAR24)

Hybrid technology can increase this number by a staggering amount, 40% in some cases. As always, specific numbers will be dependent on specific cars and their use.

Hybrid Vehicles

Cars are not the only ways hybrid technology has been applied. Hybrid trains for example are used in many countries.

Other classes of large machines have also adopted hybrid technology – for example, hybrid trucks, hydraulic machinery, ships, buses, cranes, aircraft, and even submarines. However, with large vehicles, conversion loss means there is an advantage in relaying power through mechanical chains, especially when powering multiple drives.

So the technology is less efficient than in automobiles. Many smaller vehicles such as mopeds, electric bicycles, and electric scooters are simple small-scale hybrids, powered by combustion engines and electric motors and, in some cases, with the addition of kinetic energy from the rider’s muscles.1

Hybrid Gas Mileage

Hybrid cars capture excess energy from combustion-driven motion to charge batteries which power an electric motor that assists the combustion engine. In some cases, the motor can power the vehicle alone.

Because of this, hybrids usually get much better gas mileage than combustion-only vehicles. Some of the best SUV hybrids, for example, can have a 40% increase in gas mileage when compared to combustion vehicles.

What Is a BEV?

Since the term EV (electric vehicle) technically encompasses all vehicles with electric motors, the term BEV (battery electric vehicle) has been adopted to specify those which use only the electric motor and have no combustion engine.

A white BEV type car parked and charging from its charging port, located on its left front fender, in a charging station with other vehicles parked along the same area.

(Image: anaterate25)

Related Reading: How Many Electric Cars in the World?

Hybrid vs Electric Cars Pros and Cons: Hybrid vs EV (Electric Vehicle)

The basic difference between hybrid and (pure) electric vehicles is that EVs run completely on an electric motor, and thus require battery recharges, either at a domestic or public station. A reasonable range for a single charge is about 200 miles.

EV recharging usually takes much longer than filling up a tank of gas – it can be a quarter of an hour to multiple hours, depending. And of course, EV charging stations are fewer and farther between than gas stations.

A Consumer Report analysis in 2023 indicated that EV cars are more efficient than hybrids and often have lower maintenance and repair costs. The two main reasons why a hybrid would be more affordable than an EV car are, first, high electricity costs compared to gas, two, lower purchasing costs.

Worth noting- EVs are often eligible for tax credits. Also, as they rise in popularity, so will EV infrastructure investment, making EV cars even cheaper and more convenient.

Pure EV vehicles are widely considered to be the successors of hybrid vehicles. They are more efficient than hybrids and are considered zero-emission vehicles (ZEV)s because they do not emit exhaust as a byproduct.

So they are obviously considered the cars with lowest CO2 emissions. The European Union has voted that all new cars sold from 2035 will be zero emission cars.

Almost all pure EV batteries are also lithium-ion, which is far more environmentally friendly than the nickel metal hydride batteries more common in hybrids.1

What Is a PHEV?

PHEV (Plug-in Hybrid Electric Vehicles) are hybrid cars that can have their batteries charged from an external charging station, as well as by the combustion engine.

Close up of a black Jeep Wrangler PHEV driving on a dirt road.

(Image: Werner Bayer26)

Most can run, fully charged, for about 30 minutes on pure electricity before reverting to regular hybrid operation.

Here is a Department of Energy Factsheet on PHEVs.17

Hybrid vs Plug In Hybrid (PHEV)

Because it is cheaper and better for the environment to drive with electricity, if the car will be used for basic commuting a PHEV will likely save you money in the long run. The biggest metric on the side of the traditional hybrid is simply the purchase price; you can pay an extra 15 percent of the value of a car for a PHEV version.

Of course, your choice should be based on specific models and specific driving needs and expectations. Other considerations which favor the PHEV are that most are available for federal tax rebates which don’t apply to traditional hybrids, and current heavy investment in plug-in EV technology means their convenience will likely increase in the near future.

Check here for laws and incentives by state relating to electric vehicles.7,18


The choice between a BEV and PHEV can be complicated but is dependent on a number of concrete factors. The first has to do with mileage.

The average American drives about 40 miles per day, which is often about the range of all-electric capacity for many PHEVs. If you regularly exceed 40 miles of driving, a BEV is a better bet for staying on electric efficiency.

A second factor is charging. Unlike PHEVs, BEVs are entirely reliant on electric charging.

If you are concerned with the availability of charging stations, for example, if you often go on road trips, a PHEV would be a safer choice.

A third factor is savings. PHEVs are often listed as cheaper than BEVs, mostly because of smaller batteries.

However, ownership costs of PHEVs are often higher because the car is more complex and less efficient. BEVs are likely a better option for long-term savings.

Additionally, depending on your location, BEVs may entitle you to exclusive federal financial incentives and tax credits.

A fourth factor is environmental impact. BEVs have the advantage here.

They have no tailpipe emissions to pollute local air quality, and the fact that they take energy from the power grid means that there are increasing options to power the car with renewable energy.17

How Does a Hybrid Car Work: Performance (It’s About Drive It’s About Power)

One of the advantages of a hybrid car is that its engine can be relatively small and light. The engine itself moves less weight as the cylinders rotate.

The cylinder displacement is smaller, so each requires less fuel, and it can simply have fewer cylinders. Thus the car carries less weight when it accelerates or drives upward.

So how does a hybrid car work and how does this trade-off translate to performance?

A white Toyota Rav 4 hybrid car on a road with background of branches and leaves.

(Image: ArtisticOperations19)

Well, it’s difficult to say without comparing apples to oranges. But there is no doubt that most commercial hybrid vehicles are most efficient for and designed to appeal to those with city commutes.

ICE vehicles are still generally favored by those looking for raw performance. However in recent years.

Pure EVs have matured into the performance market. Electrical vehicle engineers have sought to maximize the advantages of electric power over combustion and have produced extremely effective commercial ‘performance’ cars.

They really can be the best of both worlds between performance and environmental consciousness.

Should I Buy Used Hybrid Cars?

There are many factors in buying used hybrid cars, but one to consider is your prospective car’s previous use. Often you don’t want to buy a hybrid with a milage that is too low.

Batteries (the most expensive part) depreciate faster when they are not regularly used or are often discharged. In other words, you want a car that has been used fairly consistently.

How Much CO2 Does A Car Emit per Mile?

How much CO2 does a car emit per mile? Well, it depends on an enormous number of factors.

There are some estimates that have put US emissions at 411 grams of CO2 per mile and EU emissions at 228 grams of CO2 per mile. Consult this article for a fuller account.

Hybrid Car Insurance

Hybrid cars have unique parts and service needs, so often, hybrid car insurance is more expensive than insurance for standard gas-powered cars.

They are still usually more affordable to insure than purely electric cars, although the latter is quickly coming into market maturity. Nerdwallet compared insurance rates for four models of cars that are available in both gas-only and hybrid varieties.

It is worth noting that this disqualifies some popular hybrids such as the Toyota Prius which has no gas-only analogue. They found that on average, insurance for the hybrids costs 7% more than that of the gas-only versions, but there was significant variability.

Also, it is thought that hybrids appeal more to commuter drivers, and driving in heavy traffic increases the probability of an accident and claim. Insurance prices are usually higher for hybrid cars because hybrid cars have fewer common parts and service needs.

For example, battery systems and the need to use specially trained mechanics.

How does a hybrid car work may be a tough question to answer for many of its owners, but knowing the basics can help you make your next auto buying decision.8

Frequently Asked Questions About How Does a Hybrid Car Work?

Are Hybrid Cars Good for Long Distance Driving?

Hybrid cars generally are most fuel efficient in stop-and-go traffic, however, they can perform well for long distance driving. Some environmentally conscious drivers, who want an electric vehicle, may prefer a PHEV hybrid over a BEV electric vehicle, because gas is generally more available as a fuel.

What Are the Best Hybrid Cars?

US news ranks the top 5 hybrid models of 2023 as the Honda Accord Hybrid, the Hyundai Sonata Hybrid, the Toyota Camry Hybrid, the Hyundai Elantra Hybrid, and the Toyota Prius Prime, which is considered the car with the best hybrid mpg as of January 2023.9

What Are Electric Hybrid Cars?

All hybrid cars use both combustion engines and electric motors with batteries, so in that sense they are electric vehicles. However, many people use the term ‘electric vehicle’ or ‘EV’ to refer to cars exclusively powered by an electric motor but these are not hybrids.

Do Hybrid Cars Use Gas?

Hybrid cars use gas to charge electric motor batteries and to drive so, yes, hybrid cars use gas. However certain models such as PEVS, are capable of running exclusively on electrical power for short periods of time under light driving conditions.


1Wikipedia. (2023, April 23). Hybrid electric vehicle. Wikipedia. Retrieved May 22, 2023, from <>

2Barry, K. B. (2023, January 25). How Do Hybrid Cars Work? CR. Retrieved May 22, 2023, from <>

3Wikipedia. (2023, May 19). Regenerative braking. Wikipedia. Retrieved May 22, 2023, from <>

4Wikipedia. (2023, May 17). Lithium-ion battery. Wikipedia. Retrieved May 22, 2023, from <>

5Wikipedia. (2023, April 19). Environmental impacts of lithium-ion batteries. Wikipedia. Retrieved May 22, 2023, from <>

6EnergySage, Inc. (2023). Pros and cons of hybrid cars. energysage. Retrieved May 22, 2023, from <>

7Wikipedia. (2023, May 12). Plug-in hybrid. Wikipedia. Retrieved May 22, 2023, from <>

8Cohen, u. (2015, September 29). Comparing Car Insurance Quotes for Gas and Hybrid Vehicles. nerdwallet. Retrieved May 22, 2023, from <> (2023). Best Gas Mileage Hybrid Cars for 2023. iSeeCars. Retrieved May 22, 2023, from <>

10U.S. Department of Energy. (2023). How Do Hybrid Electric Cars Work? Alternative Fuels Data Center. Retrieved May 22, 2023, from <>

11Office of Federal Energy Management Program. (2023). Electric Vehicle Technology Overview. U.S. Department of Energy. Retrieved May 22, 2023, from <>

12U.S. Department of Energy. (2023). Batteries for Electric Vehicles. Alternative Fuels Data Center. Retrieved May 22, 2023, from <>

13United States Environmental Protection Agency. (2023, April 14). Used Lithium-Ion Batteries. EPA. Retrieved May 22, 2023, from <>

14DriveClean. (2021). Hybrid Electric Cars. DriveClean. Retrieved May 22, 2023, from <>

15U.S. Department of Energy. (2023). Emissions from Electric Vehicles. Alternative Fuels Data Center. Retrieved May 22, 2023, from <>

16Oak Ridge National Laboratory. (2023). Can a Hybrid Save Me Money? Fuel Economy. Retrieved May 22, 2023, from <>

17U.S. Department of Energy. (2023). Plug-In Hybrid Electric Vehicles. Alternative Fuels Data Center. Retrieved May 22, 2023, from <>

18U.S. Department of Energy. (2023). State Laws and Incentives. Alternative Fuels Data Center. Retrieved May 22, 2023, from <>

19ArtisticOperations. Pixabay. Retrieved from <>

20IsmaelMarder. Pixabay. Retrieved from <>

21Josbert Lonnee. Flickr. Retrieved from <>

22Tokumeigakarinoaoshima. Wikimedia Commons. Retrieved from <>

23GeorgeTan#1…Off permanently. Flickr. Retrieved from <>

24IFCAR. Wikimedia Commons. Retrieved from <>

25anaterate. Pixabay. Retrieved from <>

26Werner Bayer. Flickr. Retrieved from <>